ELECTROPLATING PROCESS- ALL YOU NEED TO KNOW

Electroplating is also known as electrodeposition. As the name suggests, the process involves depositing material using an electric current. This process results in a thin layer of metal being deposited onto the surface of a workpiece called the substrate. Electroplating is primarily used to change the physical properties of an object. This process can be used to give objects increased wear resistance, corrosion protection or aesthetic appeal, as well as increased thickness.

Also, ‘Electroplating’, ‘electro’ refers to electric current and ‘plating’ refers to an act of outer covering of some materials with a thin layer of a different metal.
Thus, electroplating is defined as the process of plating a layer of any metal on other material by passing an electric current.Electroplating is mainly done for avoiding corrosion of metals and for decorative purposes. Electroplating is a widely used process in many industries like automobiles, airplanes, electronics, jewelry, toys and many more.

Electroplating is conducted in an electrolytic cell. The metal to be electroplated is connected to the cathode. The electrolyte consists of the salt solution of metal with which electroplating has to be done. The electrolyte ionizes to give positively charged ions (metal ions) which move towards the anode for electroplating the desired object.

 

ELECTROPLATING PROCESS

The electroplating process uses an electric current to dissolve metal and deposit it onto a surface. The process works using four primary components:

• Anode:The anode, or positively charged electrode, in the circuit is the metal that will form the plating.
• Cathode:The cathode in the electroplating circuit is the part that needs to be plated. It is also called the substrate. This part acts as the negatively charged electrode in the circuit.
• Solution: The electrodepositing reaction takes place in an electrolytic solution. This solution contains one or more metal salts, usually including copper sulfate, to facilitate the flow of electricity.
• Power source: Current is added to the circuit using a power source. This power source applies a current to the anode, introducing electricity to the system.

Once the anode and cathode are placed in solution and connected, the power supply supplies a direct current (DC) to the anode. This current causes the metal to oxidize, allowing metal atoms to dissolve in the electrolyte solution as positive ions. The current then causes the metal ions to move to the negatively charged substrate and deposit onto the piece in a thin layer of metal.

As an example, consider the process of plating gold onto metal jewelry. The gold plating metal is the anode in the circuit, while the metal jewelry is the cathode. Both are placed in solution and DC power is supplied to the gold, which dissolves in solution. The dissolved gold atoms then adhere to the surface of the base metal jewelry, creating a gold coating.

While this process is constant, three factors can impact the quality of the plating. These factors are the following:

• Bath conditions: Both the temperature and the chemical composition of the bath impact how effective the electroplating process is.
• Part placement:The distance the dissolved metal needs to travel will affect how effectively the substrate is plated, so the placement of the anode relative to the cathode is important.
• Electrical current: Both the voltage level and the application time of the electrical current plays a role in the efficacy of the electroplating process.

 

 Common Types of Metals Used for Plating

Copper Plating

Copper layers are very decorative and are good electrical conductors. Depending on the additions, hardness can vary between 90 HV and more than 200 HV. For functional applications, a copper layer is often covered by another metallic layer.

Nickel Plating

Nickel layers are not only decorative, but also corrosion and wear-resistant. Depending on the organic additions, the deposit can exhibit hardness values between 150 and 500 HV. The metal layer may have varying levels of internal stress and ductility. Bright nickel looks yellowish in daylight and tarnishes easily; for this reason, it is commonly covered with a top layer such as chrome or gold.

Tin Plating

Tin offers a good level of conductivity, making it extremely useful in the manufacturing of various electronic parts. It is also widely used in the food production industry.

Gold Plating

Gold layers have many technical applications, related to their excellent corrosion resistance, low electrical contact resistance and good electrical and heat conductivity.

Gold layers can be deposited on a large variety of substrates such as metals, plastics, ceramics and natural materials (such as leather and wood), in all cases using an intermediate copper or nickel layer.

Silver Plating

Due to its good electrical conductivity, silver is very often used in electrical and electronic applications.

Palladium Plating

Palladium is well suited to plating applications where the prevention of oxide formation is required. It has a high melting point of 1554°C and costs less (per ounce troy) than gold. In most general electronics applications, palladium is an excellent substitute for gold.

Benefits Of Electroplating:-

Nowadays, metal has innumerable applications, and due to which they have become such an important resource that it is impossible to imagine what the world would be like without them. Our lives have been accustomed to make use of metal in different forms. For instance, we use iron rods in construction houses, make use of stainless steel in making utensils, and various different metals are used to design complex machinery.

Each and every metal has a unique set of properties and characteristic features. Some provide strength and some flexibility. But what if you want to have both properties in one metal? – Alloys! Alloys are formed by mixing different metals. Alloys are formed to get the best features of both the metals that are being mixed during the process. Alloys are becoming popular because they are more resistant to rust or corrosion as compared to other metals.

Now, here comes the role of electroplating. With the help of electroplating services, manufacturing industries make use of the good properties of precious and rare metals so as to enhance their functionality.

Electroplating is popular for providing a finishing look to the metals and improving their physical properties. The electroplating process is used in a wide range of industries for various applications. Besides the popularity of the electroplating process, very few industry outsiders are familiar with the process, what it is, and how it works. So, let’s get to know what electroplating is all about and what are its benefits.